
body {
  background-color: rgb(90, 90, 90);
}
.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  padding: 50px;
}

.loader {
  width: 60px;
  height: 60px;
  border: 4px solid #fff;
  border-left-color: transparent;
  border-top-color: transparent;
  border-radius: 50%;
  position: relative;
  animation: loading 4s linear infinite;
}

@keyframes loading {
  0% {transform: rotate(-90deg)}
  100% {transform: rotate(270deg)}
}
.loader::before,
.loader::after {
  content: '';
  display: inline-block;
  position: absolute;
  border: 4px solid #fff;
  border-left-color: transparent;
  border-top-color: transparent;
  border-radius: 50%;
}
/* 中间层 */
.loader::before {
  width: 40px;
  height: 40px;
  left: 6px;
  top: 6px;
  transform: rotate(-90deg);
  animation: loading 2s linear infinite;
}
/* 最内层 */
.loader::after {
  width: 20px;
  height: 20px;
  left: 16px;
  top: 16px;
  transform: rotate(90deg);
  animation: loading 3s linear infinite;
}
